Lift truck



" Jan. 22, 1963 w. E. KNAPP arm. 3,074,691

LIFT TRUCK Filed July 8, 1960 4 Sheets-Sheet 1 IN VEN TORS P 8 abwwmzmATTORNEY Jan. 22, 1963 w. E. KNAPP ErAL LIFT TRUCK 4 Sheets-Shet 2-Filed July 8, 1960 I TORNEY Jan. 22,1963 w. E. KNAPP ETALQ 3 07 ,6 1

LIFT TRUCK 4 Sheets-Sheet 3 Filed July 8, 1960 INVENTORS. WILLIAM E.KNAPP EDWIN F. WADLETON %)RNEY Jan. 22, 1963 w. E. KNAPP ETA]. 3,074,691

LIFT mucx Filed July 8; 1960 4 Sheets-Sheet 4 INVENTORS. WILLIAM E.KNAPP EDWIN F. WADLETON BY ATTORNEY United States Patent TRUCK WilliamE. Knapp and Edwin F. Wadelton, Les Angeies, Calif, assignors to Deere &Company, Moiine, 111., a corporation of Deiaware Filed l niy S, 1964Ser. No. 41,57 9 Qiairns. (Cl. 25d5) This invention relates generally tohand lift trucks and more particularly to lift trucks of this type inwhich the platform is raised, lowered and controlled by means of a.handle which is also usable as means for pulling or pushing the truckfrom one place to another.

The object and general nature of this invention is the provision ofmeans whereby the handle may be raised into a vertical position forpushing the truck about, which may be desirable when working in closequarters, and means whereby the handle may also be used, as by pushinggenerally rearwardly thereon, to start the lowering of the load from itsupper or transport position, in which the load is, in effect, latched inits transport position.

Another feature of this invention is the provision of new and improvedmeans for holding the lifting platform in its upper or raised position.

These and other objects and advantages of this invention will beapparent to those skilled in the art after a consideration of thefollowing detailed description, taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a perspective View of the lift truck in which the principlesof the present invention have been incorporated.

FIG. 2 is a plan view of the lift truck shown in FIG. 1.

PEG. 3 is a. side view of the lift truck shown in FIG. 1, the liftingplatform of the truck being shown in its lowered position in both FiGS.1 and 3.

FIG. 4 is a fragmentary side view similar to FIG. 3, but showing, first,the lifting platform locked in its raised position and, second, theposition the handle takes when the latter is actuated to elevate theplatform into its transport position.

FIG. 5 is a fragmentary side view illustrating the position of thehandle when it is raised so as to provide for pushing the truck from oneplace to another by pushing on the raised handle, the platform beingheld in its raised or transport position.

FIG. 6 is a view somewhat similar to FIG. 5 but showing the handle in aposition engaging certain portions of the lift plate that is pivoted tothe platform, so that after releasing the hold-up latch the handle maybe pushed rearwardly to start the platform toward its lowered position.

KG. 7 is a detail sectional view on an enlarged scale, taken generallyalong the line 77 of FIG. 2, showing the friction spring associated withthe lift plate shaft.

FIG. 8 is a detail sectional view, partially in section, showing thefront castering wheel support.

Referring first to FIGS. 1 and 2, the lift truck of this inventioncomprises a main frame 141 that is made up of a box type head 11 in theform of a front wheel support cover. The head 11 has fixed to the endsthereof a pair of generally rearwardly extending legs 14, eachconstituting a roller frame that is made up of laterally inner and outerbars 16 and 17. The front ends of the bars 16 and 17 are connected, asby welding, to the end portions of the head 11, the laterally outer bars16 being secured, as by welding, to the outermost end portions of thehead 11 while the laterally inner bars 17 extend forwardly into the head11 and are welded thereto, as indicated at 17', FIG. 2. The bars 16 and17 of each pair are rigidly interconnected 'by spacer bars 19, the upperedges of which 3,614,691 Patented Jan. 22, 1963 ICC extend a shortdistance above the upper edges of the bars 16 and 17, as indicated at19a in FIG. 4.

The rear ends of the two pairs of bars 16 and 17 are apertured ornotched, as at 21, FIG. 3, to receive a roller shaft 22 that is rigidlyfixed, as by welding, to the bars 16 and 17. A supporting roller 23 isjournaled by suitable bearing means on the shaft 22, the rollers 23supporting the rear ends of the main frame legs 14. The front portion ofthe main frame is carried on a caster wheel 27 that is generally ofconventional construction. The caster wheel 27 is journaled for rotationin a fork 29 (FIG. 8) that is swiveled in a head 31 secured by bolts 32to the upper plate 33 of the head 11.

A pair of roller shafts 36 are welded in apertures formed in the mainframe bars 16 and 17 and support rollers 37 journaled on the centralportions of the shafts 36 between spacer bushings 33 (FIG. 2). The mainframe 11) supports an elevating platform that is indicated in itsentirety by the reference numeral 41) and comprises a pair of channellegs 41 overlying the associated main frame legs 14. The platform 41also includes a cross channel 43 that is rigidly secured, as by welding,to the forward end portions of the channels 41, the cross channel 43thus tying the two channels 41 rigidly together, Front and rear portionsof each of the channel legs 41 carry front and rear roller ramp blocks45. The blocks are so located, as will be clear from FIG. 3, that thelonger angled sections 46 of the blocks 45 rest on the rollers 37 whenthe platform is in a lowered position. In the aforesaid position, therear edges 49 (FIG. 3) of the ramp blocks 45 bear against the rearspacer bars 19 of the main frame. The parts are so constructed andarranged that the inner horizontal face of each of the platform channels41 is spaced above the upper edge of the associated main frame bars 16and 17. As will be s n from FIGS. 3 and 4, whenever the platform 40 ispulled forwardly from its lowered position (FIG. 3), the ramps 4-5 moveupwardly on the rollers 37 toward its raised position until the points48 on the ramps 45 move past the tops of the associated rollers 37 afterwhich the rearwardly and upwardly angled portions 51 rest on the rollers37, as shown in FIG. 4. This determines the raised or elevated positionof the platform 40 in which the forward ends 41a of the platformchannels 41 come to rest against the rear wall 52 of the head 11.

As will best be seen from FIGS. 2, 3 and 4, latch means, indicatedgenerally at 61 is provided for releasably retaining the platform in itselevated position (FIG. 4) and Will now be described. The latch means6%) includes a latch bar 61 rockably mounted on the upper wall 33 of thehead 11 and having a rear hook end 62 adapted to engage an abutment 63fixed to the upper central portion of the cross channel 43. As will beseen from FIG. 4, when the latch bar 61 engages the abutment block 63,the platform is held in its raised position, but the platform may belowered by releasing the latch 68 and giving the platform a rearwardlydirected push, sufficient to raise the ramp points 48 to pass rearwardlybeyond the tops of the platform-supporting rollers 37.

The latch bar is rockably mounted on the head 11 by means of alatch-mounting block 65, best shown in FIG. 2, in which the bar 61 isshown as disposed between a pair of upwardly extending guide bosses 66.The latch bar 61 is held in place between the guides 66 by means of acap screw 64 threaded into an opening in the guide block 65. A spring 67is disposed between the top of the guide block 61 and the head of thecap screw 64 for yieldably holding the bar 61 in a generally horizontalposition but accommodating rocking of the latch bar 61, as by steppingon the forward end portion 61:: thereof.

The means for effecting the raising and lowering of the platform 40comprising a handle member 70, best shown in FIG. 1. The handle 7% ismade up of a handle bar 71 carrying a cross rod 72 at its upper end andsecurely fixed, at its lower end, to a lower cross bar, preferably inthe form ofa pipe 73, to the outer ends of which are fixed, as bywelding, apair of handle end plates 75; Hand grips 76 are fixed to theouter ends of the cross rod 72. The handle 7iiis pivoted for generallyfore and aft swinging about a transverse axis relative to the head 11 byvirtue of a pair of headed pins 77, each ofwhich' extends through anopening in the rear lower portion of the associated handle plate 75 andthrough an opening 81 formed in the associated end porti'on 84- of thehead 11 and through an opening 32 in the support'plate 87 6 16. 2)located between the forward end of the associated main frame bar 17 andthe rear wall 52 of the head iii; A tubular spacer S8 is disposedbetween the outer face of each end wall of the head ill and theassociated handle plate 75. The pivot-receiving openings 81 in the endportion of the head 11 are re enforced by apertu-red plates 53' weldedto the end walls of the head 11, as best shown in FIG. 2.

The handle "id is operatively connected with the platform tlfor raisingand lowering the latter by novel means that will now be described.Referring first to FIGS. 1, 3 and '4, lifting means is swingablyconnected with the channel 43 of the platform 4t) and includes a pair oflift plates 91 fixedly connected, as by welding, to a cross shaft 93that extends through apertures in end members 94 that are welded inposition between the end portions of the cross channel43. The endmembers 94 are apertured to receive the cross shaft 93, and spacers 96'(FIG. 2) are disposed'between the end'members 94 of the channel 43 andthe lift plates 91; Each of the handle side members '75 carries ahexagonal socket head cap screw 95' that'is threaded into a tappedopening in the associated handle side plate 75 andis locked in place bya nut The head of each of the cap screws 95 serves as a stud enteringinto a slot 191 formed in the main portion of the associated lift platehi. Each slot Hills of particular construction. As best shown in FIGS.3-6, the slot 161- includes a main portionhaving slot ends 1% and 104and a slot'portion 1&5 that extends generally at a right angle to themain portion of the slot 101. A stud 109 is carried at each endof thehead 11 and serves as a stop, as best shown in FIGS. 1 and 3,determining the vertical position as follows:

H68. 1 and 3 show the lift truck and its load platform in the lowermostposition and the handle 70 vertical, with the lower rear portions of thehandle side plates '75 resting against the stop studs 169, whereby thehandle 79 may be employed to push the platform into position underneaththe pallet of'a load to be raised. As will be seen from FIG. 3, in thisposition the lift studs 5 are disposed in the forward ends of the slot101 whereby after the pallet has been maneuvered underneath the load,;the latter may be raised by swinging downwardly on the handle '70,swinging the latter to the position shown in FIG. 4, which motion actsthrough the lift plates 91 to shift the platform 453 forwardly andupwardly, the ramp blocks 46 moving forwardly and upwardly on therollers 37 until the rear angle faces 51 of the ramps ride up and overthe rollers 37 with the forward ends of the platform channels 41engaging the rear wall 52 of the head 11, at which time the rear end 62of the latch bar 61 snaps over the abutment 63 and thus locks theplatform at} in its raised position. The load is thus raised off thefloor and held by the latch 61. The handle may now be used to pull theload to the location desired. It will be seen from FIGS. 5 and 6 that,while the platform 46 is held in its upper position by the latch bar 61engaging behind the abutment 63, as best shown in FIGS. 5 and 6, thehandle 74? may be raised freely, without affecting the position of theload, optionally into either of twopositions, one of which is indicatedin H6. 6 in which the handle is raised past a 45 position till into aposition where the studs may enter the notches 195 in the lift plates91. With the handle 7t) in this position (FIG. 6), all that is necessaryto do to lower the load is to step on the end dla of the release latchbar er, which raises the hook end 62 out of engage rnent with theabutment block 63, after which the handle 7% may be raised a slightadditional amount, sufficient to push the platform 4% rearwardly so asto carry the ramp blocks past the tops of the associated rollers 37,after which the load lowers by gravity. The forward edge of the slot MS,as indicated at a, is disposed at such an angle that when the loadlowers the arms 91 are cammed upwardly past the studs 95.

Under many conditions, it may be desirable, while the load is held inits raised position as shown in E63. 4 and 5, to swing the handle it?into its vertical position, so as to push the truck to variouslocations, for example, and in order to do this without having thenotches 1- 35 fall into the engagement with the studs 5 as the handle ismoved from the position shown in EEG. 4 to the position shown in 5, weprovide a friction spring (FlG. 7) that is disposed within the channel43 and is provided with a curved end 13.2 frictionally engaging theshaft 93. The action of the spring ill is to stub or retard the downwardswinging of the lift links ail under the action of gravity as the studs95 move past the slots 105. If the handle '7' is raised with a fairamount of rapidity, the studs 95 will pass the notches Hi5 and move intoa position, shown in 5, at the rear ends of the slot lill, wherebyalthough the load is raised and is retained in its raised position bythe latch 61, the handle '76 is disposed in a vertical position andhence may be employed to push the truck around to different positionswhile the load is raised. Whenever it is desired to lower the load, allthat is necessary to do is to swing the handle 7 3' downwardly andforwardly with a relatively slow movement so that when the handlereaches the position shown in FIG. 6, the lift plates 1 will dropdownwardly to carry the slots or notches ltd-5 into engagement with thestuds )5. The latch 61 is then disengaged from the abutment and thehandle 7% may then be raised to start the load toward its loweredposition. Similarly, the load may be pulled around while raised on thetruck with the handle somewhere in between the position shown in FIG. 6and the position shown in 4, and then when it is desired to drop theload, all that it is necessary to do is to raise the handle 79 fairlyslowly so that the notches 165 will engage the studs 95 as the handle israised, after which the latch 61 may be disengaged by stepping on theend 61a. Raising the handle 7d further will then serve to push the leadover into its lowered position.

Each of the lift plates is provided with an extension that extendsgenerally upwardly and inwardly so that by stepping on one or the otherof the extensions 115, the side plates 91 may be held against droppingdownwardly while the handle 7t? is raised from a lower position into avertical position. Thus, regardless of whether the handle 7B is raisedrapidly or slowly, stepping on one of the extensions 115 will preventthe lift plates 91 from engaging their notches 1&5 with the studs 95 onthe handle.

While we have shown and described above the preferred structure in whichthe principles of the present ina vention have been incorporated, it isto be understood that our invention is not to be limited to theparticular details, shown and described above, but that, in fact, widelydifferent means may be employed in the practice of the broader aspectsof our invention.

What we claim, therefore, and desire to secure by Letters Patent is:

1. A hand lift pallet truck comprising a mobile frame. an elevatableplatform carried thereby, means intercon meeting said frame and platformwhereby when the latter is moved in one direction relative to the framethe platform is raised, an oscillatable handle pivoted to the mobileframe and connected with said platform to, shift, the latter.

in said one direction, a latch guide fixed to the forward central partof said frame and having laterally spaced apart guide shoulders, amember mounted between said guide shoulders and extending upwardlytherefrom, a latch bar disposed between said shoulders and held therebyagainst lateral displacement, said latch bar being adapted to pivotabout said member, spring means mounted about said member and actingagainst the top of said bar to normally hold the latter in a generallyhorizontal rearwardly extending position, means on the platform tointerlock with the rear portion of said latch bar when the platform israised, and the forward portion of said latch bar extending beyond saidlatch guide and acting when depressed to release the rear portion of thelatch bar from said platform.

2. A hand lift pallet truck comprising a mobile frame, an elevatableplatform carried thereby, means interconnecting said frame and platformwhereby when the latter is moved in one direction relative to the framethe platform is raised, and releasably retained in that position, anoscillatable handle pivoted to the mobile frame, a lift plate pivoted tothe forward portion of said platform and extending forwardly andupwardly toward said handle, the latter carrying a stud and said liftplate having an elongated opening forming slot adapted to receive saidstud, said elongated opening being provided with first and secondportions into either of which said stud may be disposed, one portionbeing disposed closer to the pivot of said lift plate than the otherportion, said one portion adapted to receive said stud and so locatedthat when said stud is disposed in said portion an upward movementimparted to said handle serves to shift said platform into a releasedposition to permit the platform to lower.

3. The invention set forth in claim 2, further characterized by said oneportion having a stud-engaging wall angled so that said lift plate iscammed out of engagement with said stud to accommodate complete loweringof said platform.

4. A hand lift pallet truck comprising a mobile frame, an elevatableplatform carried thereby, means interconnecting said frame and platformwhereby when the latter is moved in one direction relative to the framethe platform is raised, and releasably retained in that position, anoscillatable handle pivoted to the mobile frame and swingable between agenerally vertical position to a generally horizontal position,connecting means between said handle and said platform whereby movementof said handle from its generally vertical position to its generallyhorizontal position moves said platform in said one direc- .tion intoits raised position, and said connecting means including a stud on thehandle and a member having an elongated opening forming a slot receivingsaid stud and pivoted to the platform, said elongated opening being provided with a portion to receive said stud and so located that when saidstud is disposed in said portion, a rearward 6 push on said handle willinitiate the lowering action of said platform.

5. The invention set forth in claim 4, further characterized by stopmeans on the frame defining the upper limit of movement of the handle,and said portion being angled so that after the handle has been broughtup against said stop means continued downward movement of the platformdisengages the portion from said handle stud.

6. The invention set forth in claim 5, further characterized by anextension on said slotted member serving as a foot pedal to provide forholding said slotted member in a position disengaging the said portionfrom said handle stud.

7. The invention set forth in claim 4, further characterized by stopmeans on the frame defining the upper limit of movement of the handle,said stop means being located so that the pallet truck may be moved by apush on said handle While the platform is retained in its raisedposition.

8. The invention set forth in claim 1, further characterized by saidinterconnecting means comprising a plurality of rollers carried by saidmobile frame, and a plurality of members having inclined surfaces, saidmembers being carried by said platform and adapted to contact therollers.

9. A hand lift pallet truck comprising a mobile frame having a forwardend and a rearward end, an elevatable platform carried thereby, meansinterconnecting said frame and platform whereby when the latter is movedforwardly relative to the frame the platform is raised, an oscillatablehandle pivoted to the mobile frame and connected with said platform toshift the latter forwardly, said interconnecting means comprising aplurality of rollers carried by said mobile frame, and a plurality oframp blocks carried by said platform, each of said ramp blocks having agenerally V-shaped lower surface comprising a forwardly downwardlyinclined surface and a rearwardly downwardly inclined surface, said rampblocks contacting the rollers, and stop means fixedly secured to themobile frame and engageable by said platform, the parts being soarranged and constructed that when the platform is in its raisedposition, the forwardly downwardly inclined surface of the ramp blocksare in contact with the rollers, and the weight of the elevatableplatform tends to roll said platform forwardly into abutting positionagainst said stop means.

References Cited in the file of this patent UNITED STATES PATENTS1,577,894 Carr Mar. 23, 1926 1,662,782 Scriven Mar. 13, 1928 1,875,762Remde Sept. 6, 1932 2,130,939 Williams Sept. 20, 1938 2,251,606 WobbeAug. 5, 1941 2,424,417 Quayle July 22, 1947

2. A HAND LIFT PALLET TRUCK COMPRISING A MOBILE FRAME, AN ELEVATABLEPLATFORM CARRIED THEREBY, MEANS INTERCONNECTING SAID FRAME AND PLATFORMWHEREBY WHEN THE LATTER IS MOVED IN ONE DIRECTION RELATIVE TO THE FRAMETHE PLATFORM IS RAISED, AND RELEASABLY RETAINED IN THAT POSITION, ANOSCILATABLE HANDLE PIVOTED TO THE MOBILE FRAME, A LIFT PLATE PIVOTED TOTHE FORWARD PORTION OF SAID PLATFORM AND EXTENDING FORWARDLY ANDUPWARDLY TOWARD SAID HANDLE, THE LATTER CARRYING A STUD AND SAID LIFTPLATE HAVING AN ELONGATED OPENING FORMING SLOT ADAPTED TO RECEIVE SAIDSTUD, SAID ELONGATED OPENING BEING PROVIDED WITH FIRST AND SECONDPORTIONS INTO EITHER OF WHICH SAID STUD MAY BE DISPOSED, ONE PORTIONBEING DISPOSED CLOSER TO THE PIVOT OF